Known elevator systems usually comprise a trapping system, which is designed to decelerate a free-falling elevator car and bring it to a standstill, and a drive brake, which is arranged near to an elevator drive and brakes the elevator system in operation, for example when stopping. EP2107029 discloses a corresponding brake system with a drive brake and a trapping device. The brake system has a brake control device, which initializes an appropriate braking action in the event that an abnormal condition is detected.
The drive brake system must be able to securely bring an elevator car to a stop and hold it in place in the event of a fault. For safety reasons, all parts of the drive brake system are implemented in duplicate. As a result, essential parts of the drive brake are present in duplicate, so that in case of failure of one of the drive brakes, safe braking of the elevator car is still guaranteed.
The trapping device or trapping system must be capable of braking the elevator car to a standstill and halting it in case of failure of supporting equipment or the support system in general.
Additional brakes are often also arranged on the elevator car (car brake system), which can also brake the elevator car slightly and therefore damp vibrations of the elevator car.
In some cases, car brake systems are also used which completely replace the drive brakes and which can safely temporarily halt and stop the elevator car. In this solution also, essential parts of the car brake system are implemented in duplicate. In this case, one effect of the redundancy of the brake system is to cause a weight increase of the elevator car, so that more powerful drives and more support equipment may be necessary. In other cases, overall braking power is available which is far in excess of requirements. This in turn gives rise to higher procurement and maintenance costs.